The Grenada gazette. (Grenada, Miss.) 1885-18??, 1887-07-02
SAND MANUFACTURE.
now Silica Ia Ground Down and Washed
for GLASS; Making Purpose.

Wv" SuiCN II utOuuu Down 40Q W44de0
for Glass-Mskins Purposes.
The manufacture of sand is an i'm.
portant industry. which has Pittsburgh
for its Headquarters. although the sand
is not made within the limits of the
city. There is considerable traffic in
Monongahela sand. which is scooped
up from the bed of the river, to be used
for common building purposes; but the
manufacture Of sand is quite another
affair. and the product goes into quite
a different commodity, which is glass.
Practically glass is almost pure
sand, other substances used in its
manufacture for fuxing being con
sumed while the sand is tranformed to
a greater or less degree of Transparent.
cy. The sand used in glass-making is
almost pure silica, so neatly pure that
there is less than n per cent of iron.
magnesia and aluminium. to ninety
nine \ per cent of the other. And of
this sand. which is quarried on: of the
hills and ground down to varying de-
grees Of wilderness. eight hundred tons
are manufactured daily, four hundred
tons being consumed in and abou,
Pittsburgh, and four hundred tons GO
ing into Eastern Ohio and West vir-
ginia to Wheeling. Bellaire, Columbus.
and all points within a circuit OF one
hundred and fifty miles from Pitts
burgh.
In selecting, a darkish sand is found.
containing more foreign substances
than the ninety.nine per cent. silica.
which inferior grade goes into green
or ''black' bottles. and a still darker
and baser earth, which is used for
sanding friedrich molds; another and
finer dark grade, which is used by
crucible-steel manufacturers; and still
another quality. the whitest and gritti.
est. which becomes flint" or what
might be called absolutely transparent
glass. An inferior quality of white
sand is used for prescription-bottles,
but the very best is for the higher
grade of fint-ware.
Looking through the fiat surface OF
window-glass, whether plate or blown.
1t appears colorless; but. ii the sight is
directed through the edge, it will dis
close a sea-green tinge. Flint-glass
proper is not so. 1t is absolutely col.
orless, except when cut into faces or
prisms, when it reveals the colors Of
the spectrum.
The cost of o ton Of sand to glass
manufacturers Of Western Pennsyl.
vania, Eastern Ohio or West Virginia
is, of course. dependent on the dis
lance it is hauled from the quarry; but
taking the eight hundred tons daily
manufactured and consumed, it will
not average above 1925 per ton,
damp. Dried sand will average $2.5O
per ton. OF course, it costs n little
less than those figures in Pittsburg.
and a little more in Bellaire. Ohio; but
at this last-nsmed place, the cost
of the sand which goes into the manu-
facture Of a box of common window
glass, containing tho regulation fifty
feet Of surface. is about five
cents; that is, the box Of glass consists
Of FIVE cents worth Of silica.
transmitted to q state of transpar.
ency. !
The sand used in the glass industry
In Western Pennsylvania. Eastern
Ohio and West Virginia, comes from
three quarries; one on the P%ennsylva-
mia railroad. overlooking the Juniata;
one on the Baltimore & Ohio railroad.
near Conceivable; and n On the Nc.
.eesport & Youghiogheny railway.
twenty-five miles south Of Pittsburgh.
Is quarried out like building-stone,
through a quartz-crush"r.
reduced under immense iron
and finally ground and washed
In an endless screw. The washing re.
leases some of the foreign substances.
but streaks of iron which are some.
times found running through the stone
are knocked of to undergo the mill.
Ing process for the inferior quality Of
some Of which goes into mortar
Tor specially fine and durable wall
building. The railroads use large
quantities Of 1t in the construction OF
retaining.walls for embankments.
And so all grades Of the sand are util-
led. Popular Science Monthly.